Remnants of what appears to be an RBK-500 AO-2.5RT cluster bomb uncovered near Chalai, Sri Lanka.
Photograph: Source

Images that appear to confirm the use of cluster bombs in the end stages of Sri Lanka’s 26-year civil war have been uncovered as new testimony emerged suggesting the country’s armed forces may havedeployed the munition against civilians.

The revelations are likely to prompt serious questions for the current Sri Lankan government, which includes several senior members of the cabinet who oversaw army activity during the last days of the conflict.

The photographic evidence provided to the Guardian depicts cluster bombs uncovered by de-mining teams in parts of the country close to sites where fighting took place in late 2008 and early 2009.

The material is accompanied by the testimony of former de-miners, some of whom claim they identified munitions within government-declared “no fire zones” in which about 300,000 people were told to gather for their safety during the war’s denouement.

The Sri Lankan civil war, which lasted from 1983 to 2009, pitted the country’s military against the separatist rebel force known as the Liberation Tigers of Tamil Eelam (LTTE) which had waged an armed campaign to achieve an independent state for the ethnic Tamil community in the north and east of the island nation.

The bloody conflict is estimated to have claimed upwards of more than 100,000 lives, many of them in the final months of fighting which occurred in and around the northern Vanni region.

An image of what appears to be an unexploded AO-2.5RT cluster submunition found near Chundikulam.

The current president, Maithripala Sirisena, held the position of acting defence minister immediately before the war ended, taking over temporarily from Mahinda Rajapaksa who was abroad. Rajapaksa’s brother, Gotabhaya, the defence secretary, was regarded as having directed much of war strategy.

A leading member of Sirisena’s current cabinet, Sarath Fonseka, was commander of the army.

The photographs of cluster bombs were leaked to the Guardian by a former employee of the Halo Trust, the world’s largest mine clearance organisation. The images appear to show members of the trust digging out a large delivery missile as well as cluster submunitions, or “bomblets,” in different locations.

Independent corroboration of the nature of the weapons has been provided by a senior weapons researcher at Human Rights Watch who identified the material pictured as the remnants of Russian-made cluster bombs and unexploded cluster submunitions.

The revelations come as the 32nd session of the Human Rights Council opened last week in Geneva, at which the Sri Lankan government is to be questioned on its progress to provide accountability for alleged war crimes committed during the war’s close.

Reports produced by the United Nations and several rights groups have found that war crimes and possible crimes against humanity may have been committed by Sri Lankan forces; so far no senior member of the government or armed forces has been held accountable.

Towards the end of the war, while closing in on the LTTE’s last redoubts in the vicinity of Puthukudiyiruppu and Mullaitivu, the government advised civilians to gather in a series of “no fire zones” – areas which the Sri Lankan army promised it would not attack. The location of the safe zone shifted three times, moving from an initial 20-square-mile (52 sq km) block around the area of Suthanthirapuram to a narrow strip of coastland, which shrunk even further as the army made gains.

Cluster bomb image from Chundikulam, Sri Lanka. Human rights watch has documented their use in Georgia, Sudan, and quite extensively in Syria.

He has committed himself to holding a war crimes tribunal in Sri Lanka, but has so far resisted calls to conduct such a hearing in a “hybrid” court that would involve both Sri Lankan and international legal experts, as recommended by a UN report released in 2015.

Cluster bombs are distinguished by their capacity to explode and release smaller submunitions that scatter over a wide area. Their inherently indiscriminate nature means their deployment in populated areas could amount to war crimes, as the UN secretary general, Ban Ki Moon, observed earlier this year, citing alleged incidents in Yemen.

In communications with the Guardian, a spokesperson for the Halo Trust acknowledged it had found a total of 42 cluster munitions in several sites around the Pachchilapalli area, near Elephant pass, slightly to the north of the Vanni region, in 2011 and 2012.

While Halo did not comment on the provenance of the weaponry, the area saw heavy fighting between government forces and the LTTE in 2009. The trust stressed it did not engage in de-mining within the “no fire zone”.

The source for the photographs, who now lives outside Sri Lanka, said the images depicted munitions discovered in the Kilinochchi district and also near Chalai, to the north of Mullaitivu. Both Chalai and parts of Kilinochchi district were also sites of fierce battles in the final months of the conflict.

During the war, allegations of the use of cluster bombs in several sites around the Vanni emerged, but were never proven; reports produced for the UN secretary general and the US government cited credible allegations of wartime cluster bomb use in several sites including the no fire zone.

Munitions found in a ‘densely civilian-populated area’

Further evidence suggesting government forces were responsible for the attacks has now been provided in the form of the testimony of former employees of three different de-mining teams who spoke anonymously to the Guardian.

Ex-workers at Mines Advisory Group (MAG), the Halo Trust and the Swiss Foundation for Mine Action (known by its French-language acronym FSD) have said they saw evidence of the use of cluster bombs in the final days of the war, with representatives from the final two saying cluster bombs were found in one of the government-declared no fire zones.

Only the Sri Lankan air force and army are believed to have had the capability to deploy cluster bombs in the no fire zone; the LTTE did not undertake aerial attacks in the area.

Their accounts are supported by those of civilian witnesses in Sri Lanka and abroad, as well as a former aid worker, all of whom spoke on condition of anonymity.

De-mining agencies do not typically make their discoveries public, but they are required to report their findings to the the Sri Lankan national mine action centre, a coordinating body supported by the Sri Lankan government and the UN.

Remnants of an AO-2.5RT antipersonnel submunitions being dug up in Kilinochchi district in Sri Lanka.

Former officials in two de-mining organisations told the Guardian that cluster munitions were positively identified.

An ex-employee at MAG, who asked not to be named for his own safety, told the Guardian the organisation encountered a munition in a “densely civilian-populated area” in one of the no fire zones near Puthukudiyiruppu, the location around which a UN Development Programme (UNDP) had reportedly found munitions in 2012.

Cluster bomblets were found, he said, recalling that “all the scattered parts were gathered in the same spot” however, MAG did not publicly share the information “because of their security concerns”.

Another former de-mining official, formerly with the Swiss NGO FSD, recalled that a “technical adviser confirmed [that they had found cluster bombs] ... but it did not publicise this.”

He said the weapons were discovered in 2010 in the area of the first no fire zone, by the village of Suthanthirapuram, also near Puthukudiyiruppu. Any move to make their discoveries public were inhibited by fear of retribution, he added.

Both demining groups were approached for comment: MAG did not immediately respond, while FSD declined to issue a statement.

The source who leaked the photographs from Halo alleged the de-mining team was extremely wary of reports of “cluster bombs” discoveries as they feared retributive action by the Rajapaksa regime.

A spokesperson from Halo said the organisation “strongly refutes any suggestion that any information of this nature would be withheld from the requisite authorities by its senior management.

“We take our reporting responsibilities extremely seriously. I can confirm that every item of ordnance found by Halo in Sri Lanka – and indeed in all the countries in which we operate – is itemised in our monthly reports, which are submitted to national authorities.

“This is the case now and always has been ...As a neutral organisation, Halo’s responsibility is to ensure the safety of civilians from explosive remnants of war.”

An NGO worker for an international aid organisation who asked for his identity to be protected told the Guardian he witnessed cluster attacks within the second and final no fire zone near Mullaitivu, and saw unexploded munitions which resembled a bicycle “dynamo” with a “small piece of ribbon also fixed in one side”.

“Most of the INGOs put the sample pictures of the cluster bomb in their notice board and [made their staff] aware ... about this risk,” he added.

A witness interviewed by the Guardian in Australia who claims to have witnessed a cluster bomb attack on Puthukudiyiruppu hospital recalled: “The cluster bomb would explode high up and small explosions would hit trees and people.”

There would be a smell that would turn your stomach

Cluster bombing witness

The witness described the sound as “like you’re hitting something repeatedly”, adding “there would be a smell that would turn your stomach. People would smell, there would be a burnt odour to it.” The source had previously testified to a UN war crimes inquiry and was deemed credible.

Another witness whose testimony was gathered for the UN’s 2015 war crimes investigation, told the Guardian that cluster bombing was “something that continuously happened in the protective [no fire] zones. This wasn’t fulfilling war purposes. It hit civilians.”

Sam Zarifi, regional director of Asia and Oceania for the International Commission of Jurists, told the Guardian: “These most recent allegations highlight the need for a credible, effective accountability mechanism.”

Jan Jananayagam, head of Together Against Genocide, a non-profitthat also obtained the leaked photographs, said: “Seven years have passed and the government of Sri Lanka is still in denial about the types of weapons deployed on Tamil civilians.

“The denial of the use of cluster munitions and the destruction of forensic evidence over the past seven years illustrates exactly why it is critical that international investigators and forensic experts be included in any future war crimes prosecution mechanism.”

The Sri Lankan government was contacted in preparation for this article but did not immediately respond to requests for comment.